The present invention relates to a data-processing apparatus, a data-processing method adopted in the data-processing apparatus and programs prescribing the data-processing method.
As the storage capacities of random-accessible disc recording mediums such as optical discs and HDs (Hard Discs) increase and the prices of such recording mediums decrease, non-destructive editing works can now be carried out on video and audio data recorded on an optical disc as data having a high-bit rate.
The non-destructive editing work is an editing process adopting an editing method for merely setting so-called edit points, namely, IN and OUT points, in AV data recorded on an optical disc as an edit material but not editing (or destructing) the edit material itself. In a non-destructive editing process, there is typically created a list of edit points set at the edit time. The list of edit points is referred to hereafter as a play list. A result of a non-destructive editing process is then reproduced in accordance with a play list created for the edit material. That is to say, a result of a non-destructive editing process carried out on an edit material recorded on an optical disc is reproduced by reproducing the edit material in accordance with edit points described on a play list created for the edit material. If an editing work other than the non-destructive editing processing needs to be carried out on an edit material completing an irreversible process such as an MPEG encoding process, the edit material must be first decoded, results of the decoding process are then connected to each other and the decoding results connected to each other are finally subjected to an MPEG encoding process. By carrying out the non-destructive editing processing, however, such decoding and encoding processes do not have to be repeated so that the picture quality can be prevented from deteriorating due to repeated decoding and encoding processes.
It is to be noted that, if an edit material is connected to another edit material in a non-destructive editing process, a special effect may be attached to the junction between the edit materials in some cases. If a special effect is attached as such in a non-destructive editing process, in an operation to reproduce the result of the editing process, it is necessary to read out the two edit materials on both sides of the junction with an attached special effect from an optical disc and to attach another special process to the junction. For this reason, in accordance with Japanese Patent Laid-open No. Hei 11-146330 and a U.S. application identified by a Ser. No. of 09/185,021 as a U.S. application associated with Japanese Patent Laid-open No. Hei 11-146330, only the junction to which another special effect is to be attached is recorded in advance.
By the way, a clip is defined as a collection of edit-material data between an edit point (that is, an IN point) and the next edit point (that is, an OUT point). Thus, a result of a non-destructive editing work can be reproduced in clip units. Different clips may be recorded in recording areas separated from each other on an optical disc.
Thus, a reproduction process based on a play list may transit from a specific clip to a next one. In this case, in a disc apparatus for reproducing these clips recorded on an optical disc, it is necessary to carry out a seek operation from a recording area for recording the specific chip to a recording area for recording the next clip.
If it takes much time to complete such a seek operation, the reproduction process may be unavoidably interrupted.